[OpenJDK 2D-Dev] JDK 9 RFR of JDK-8132500: Add imageio test to tier 3

[joe darcy]

Hello,

Please review the small patch below to address

     JDK-8132500: Add imageio test to tier 3

by adding the jdk_imageio test group to tier 3.

Thanks,

-Joe

diff -r 1d42e865f18c test/TEST.groups
--- a/test/TEST.groups    Thu Jul 23 16:46:54 2015 +0300
+++ b/test/TEST.groups    Tue Jul 28 21:00:02 2015 -0700
@@ -43,7 +43,8 @@

  tier3 = \
      :jdk_rmi \
-    :jdk_beans
+    :jdk_beans \
+    :jdk_imageio

  ###############################################################################
  #